November 16, 2012
Germany

Hybrid tower pushes turbine height to 200 meters

by Nic Sharpley | Windpower Engineering & Development | November 16, 2012 | www.windpowerengineering.com

Wind turbine manufacturer, REpower Systems SE (www.repower.de), has commissioned its tallest wind turbine to date. Located in Bavaria at the Winnberg site, the turbine has a power rating of 3.2MW, a rotor dia. of 114m, and it sits on a 143-m concrete and steel hybrid tower. Rotor tips will reach to a height of 200m. The company says the turbine is best suited for locations with low-wind speeds, such as hilly terrain and forested areas.

“We can gain an additional energy yield of up to 1% with the hub height above 100m,” says Matthias Schubert, Chief Technical Officer, REpower Systems SE. And by raising the hub height from 93m to 143m the company expects an increase in yield of up to a whopping 50% in low-wind locations.

The hybrid tower is a combination of pre-manufactured steel-concrete segments and a standardized steel tower, which is already being used with the REpower 3.4M104 that has a 128m hub height. “The hybrid design permits extending towers by up to 50% higher and overcoming natural site limitations. The segmented construction also supports an economic, nearly weather-independent installation, and guarantees a relatively short construction time,” says Schubert. The increase in hub height also brings new challenges with transport and installation.

So an important component of the technical design is a mobile tower crane, which REpower first deployed during the erection of the wind turbine at the Winnberg site. The crane “climbs up” along with the progress of construction, thus permitting a cost and space-saving installation of the turbine even in forested areas and on complex terrain. With this concept, the time ordinarily required for onsite installation is significantly reduced, says the company.

In September, REpower announced the expansion of its 3.XM series which includes the launch of a new turbine type, the 3.0M122. The first variant of the new low wind speed turbine with a hub height of up to 139 metres will be on sale starting in early 2013. The existing turbines from the 3-megawatt class – the 3.2M114 and 3.4M104 – are being certified for use at sites with higher wind speeds. The 3.2M114 will be available in three hub heights (93m, 123m, and 143m) in the corresponding IEC II wind class starting for mid-2013. In addition to certification for IEC classes, the turbines are also being certified for the highest wind zones and terrain categories in accordance with the German DIBt guidelines. WPE